Approved under EASA DOA No. 21J.056. Page 1/15

 2008.08.18 This document is available on the internet: www.eurocopter.com/techpub 

 EUROCOPTER

DIRECTION TECHNIQUE SUPPORT

13725 MARIGNANE CEDEX FRANCE 

 

 EMERGENCY

ALERT SERVICE BULLETIN 

DAUPHIN NUMBER VERSIONS 

Civil: N, N1, N2, N3 365 05.00.51 Military: F, Fs, Fi, K 

AA, MA, MB, SA, SB, 565 05.00.21 Military: UB

Civil: G1 366 05.35 Military: GA 

C, C1, C2, C3 365 05.28 Civil:

SUBJECT: TIME LIMITS - MAINTENANCE CHECKS 

 Check of the Bushes and Check for Absence of Delamination on Starflex 

 Star Arm Ends 

ATA: 62

REVISION No. DATE OF APPROVAL DATE OF ISSUE 

 

Revision 0 On: March 31, 2006 2006.04.04 

Revision 1 On: October 12, 2006 2006.10.12 

Revision 2 On: November 16, 2007 2007.11.22 

Revision 3 On: August 18, 2008 2008.08.18 

 
 

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1. PLANNING INFORMATION 

1.A. EFFECTIVITY 

1.A.1. Helicopters/Installed equipment 

Bushes and composite material on the arm ends of main rotor hub Starflex stars (all part numbers). 

1.A.2. Non-installed equipment 

Not applicable. 

1.B. ASSOCIATED REQUIREMENTS 

Not applicable. 

1.C. REASON 

To render inspection checks of the bushes installed on Starflex star arm ends mandatory and to reduce the 

interval between successive checks in order to be able to detect any bush bonding failure or distortion of a 

Starflex arm end as rapidly as possible. 

Revision 0 of this ALERT SERVICE BULLETIN which formed the subject of an EASA Airworthiness Directive 

supersedes ALERT TELEX No. 05.00.51, issued on September 27, 2005, with no change to the technical 

content. 

Revision 1 of this ALERT SERVICE BULLETIN added to the inspection checks of the bushes on the Starflex 

star arm ends, a visual check for absence of delamination on the star arm ends, on the horizontal center 

plane, flush with the bush. 

Revision 1 of this ALERT SERVICE BULLETIN formed the subject of an EASA Airworthiness Directive. 

Revision 2 of this ALERT SERVICE BULLETIN specified that local loss of the adhesive bead on stars fitted 

with shouldered bushes (post MOD 0762C18) is no longer to be considered as a reason for removal on the 

condition that part of the adhesive bead remains on the leading edge thus enabling to check that there is no 

gap E1, as shown on Figures 1, 3 and 5. 

Revision 2 of this ALERT SERVICE BULLETIN has no effect on the content of EASA Airworthiness 

Directive 2006-0321-E which remains unchanged and is still applicable. 

The purpose of Revision 3 of this ALERT SERVICE BULLETIN is to rewrite the “Operational Procedure” 

paragraph 2.B. and clearly describe in paragraph 2.B.1 all the various types of deterioration that may be 

discovered during the visual inspection of the adhesive bead on the bushes installed on Starflex star arm ends. 

Revision 3 of this ALERT SERVICE BULLETIN will form the subject of an EASA Airworthiness Directive.

Revision 3 of this ALERT SERVICE BULLETIN does not affect compliance with Revision 2.
 

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1.D. DESCRIPTION 

Revision 0: 

In ALERT TELEX No. 05.00.51, EUROCOPTER informed you of two cases of deterioration of the 

end of one of the Starflex star arms: 

- The first case concerns a helicopter on which high-amplitude vibrations occurred in flight, compelling the 

pilot to carry out a precautionary landing. On the ground, it was then found that the end of a Starflex star 

arm had failed in line with the bush. 

- The second case concerns significant dragwise distortion of a Starflex star arm end. This distortion was 

discovered during a maintenance inspection and was indicated by a significant gap between the adhesive 

bead and the bush leading edge. 

In both cases, the customers had discovered cracking or local loss of the adhesive bead during a scheduled 

inspection check, carried out sometime before. A photo showing an example of deterioration (existence of a 

gap between the adhesive bead and the bush) discovered on the bush on a Starflex star arm end, is 

provided on Figure 3. 

The check for correct bonding of the bushes installed on the Starflex star arm end was therefore required 

every 50 flying hours 

Since the ALERT TELEX was issued, the two Starflex stars concerned have been received and examined by 

EUROCOPTER. These examinations revealed accidental deterioration for the first case (FOD) and 

progressive deterioration for the second case. 

EUROCOPTER is currently analyzing the mode of deterioration for the second case in order to define any 

possible modification(s). 

Pending completion of these analyses and in order to make it possible to detect any bush bonding failure or 

Starflex star arm end distortion as rapidly as possible, EUROCOPTER has rendered the monitoring, defined 

in ALERT TELEX No. 05.00.51, issued on September 27, 2005, mandatory. 

Revision 1: 

EUROCOPTER informed you of a new case of failure of a STARFLEX star, flush with the bush on the star 

arm end. 

This event was indicated by high-amplitude vibrations in flight, compelling the pilot to carry out a 

precautionary landing which took place with no other damage. 

The star concerned was returned to EUROCOPTER for investigation. 

Preliminary examinations revealed delamination on the center plane, on the star arm end, similar to the initial 

case. A photo showing an example of the delamination found on the arm end is provided on Figure 4. 

The elements currently in our possession seem to indicate that the hypothesis established in the initial case 

(FOD) is not confirmed. 

Without predicting the results of the ongoing investigations and in view of these initial findings, 

EUROCOPTER provides additional information concerning the star removal criteria defined in this ALERT 

SERVICE BULLETIN. 

Given the compliance time for this additional check, EUROCOPTER issued these instructions through an 

ALERT SERVICE BULLETIN. 
 

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Revision 2: (See Figures 1 and 5) 

Since the Starflex stars post MOD 0762C18 (Starflex stars P/N 365A31-1210 all dash numbers and 

P/N 365A31-1211 all dash numbers, manufactured from a new material and fitted with a shouldered bush on 

each star arm end) were put into service, numerous customers have reported cases of local loss of the 

adhesive bead (2) or the shockproof paint (3) from the flange/shoulder of the bush (1) on the star arm end. 

With this design standard, the adhesive bead (2) is added after bonding the bush (1), and does not at all 

feature the same bonding quality as the previous design standard. Consequently, with this type of stars, 

there is a risk of local loss of the adhesive bead (2) in operation. This, however, is not indicative of a 

deterioration of the bonding quality of the bush (see Figure 5). In this case, only delamination on the star arm 

end 

(Figure 4), de-bonding of a bush or distortion of a star arm end (existence of a gap (E1) between the 

remaining part of the adhesive bead (2) and bush (1): Figures 1 and 3) must be considered as a reason for 

removal. 

Therefore, in Revision 2 of this ALERT SERVICE BULLETIN, EUROCOPTER modifies the removal criterion 

for Starflex stars post MOD 0762C18 with respect to the adhesive bead. 

Revision 3: 

Revision 3 of this ALERT SERVICE BULLETIN does not modify the previous criteria and time limits defined 

in the previous revisions. Revision 3 provides some additional information concerning the analysis of the 

various deteriorations that may be discovered at the bonding interface between the bush (1) and the Starflex 

star arm end. 

1.E. COMPLIANCE 

The following measures are mandatory from receipt of Revision 0 of ALERT TELEX No. 05.00.51, issued on 

September 27, 2005. 

1.E.1. Compliance at the works 

1.E.1.a. On helicopters/installed equipment: Comply with paragraph 1.E.2.a. 

1.E.1.b. On non-installed equipment: Not applicable.

1.E.2. Compliance in operation: By the operator. 

1.E.2.a. On helicopters/installed equipment: 

- Comply with paragraph 2.B. within the 10 flying hours following receipt of ALERT TELEX No. 05.00.51, 

issued on September 27, 2005, 

then, 

. comply with paragraph 2.B. every 10 flying hours. 

1.E.2.b. On non-installed equipment: Not applicable. 
 

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1.F. APPROVAL 

Approval is limited to civil version helicopters subject to an Airworthiness Certificate. 

The technical information contained in Revision 0 of this ALERT SERVICE BULLETIN was approved 

on March 31, 2006 under the authority of EASA Design Organisation Approval No. 21J.056. 

The technical information contained in Revision 1 of this ALERT SERVICE BULLETIN was approved 

on October 12, 2006 under the authority of EASA Design Organisation Approval No. 21J.056. 

The technical information contained in Revision 2 of this ALERT SERVICE BULLETIN was approved 

on November 16, 2007 under the authority of EASA Design Organisation Approval No. 21J.056. 

The technical information contained in Revision 3 of this ALERT SERVICE BULLETIN was approved 

on August 18, 2008 under the authority of EASA Design Organisation Approval No. 21J.056. 

1.G. MANPOWER 

Qualification: Mechanic. 

Time for the operations: Approximately 15 minutes. 

1.H. WEIGHT AND BALANCE 

Not applicable. 

1.I. EFFECT ON ELECTRICAL LOADS 

Not applicable. 

1.J. SOFTWARE MODIFICATION EMBODIMENT STATE 

Not applicable. 

1.K. REFERENCES 

Maintenance Manual (MET) Work Card: 62.20.00.401 or 65.14.401. 

1.L. OTHER DOCUMENTS CONCERNED 

Maintenance Program (PRE). 

Maintenance Manual. 
 

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1.M. TOOLING CONCERNED 

Not applicable. 

1.N. INTERCHANGEABILITY AND MIXABILITY OF PARTS 

Not applicable. 
 

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2. ACCOMPLISHMENT INSTRUCTIONS 

2.A. GENERAL 

Not applicable. 

2.B. OPERATIONAL PROCEDURE 

2.B.1. Visual check of the adhesive bead on the bushes on the Starflex star arm ends 

As per Figures 1, 2, 3 and 5: 

On each arm of the Starflex star, check that the bonding of the bush has not failed and that the arm ends are 

not distorted; see the bush installation drawing on Figure 1, according to star definition. This check may 

reveal various types of occurrences which are described in paragraphs a), b) and c): 

a) cracking of the shockproof paint (3) over the circumference of the adhesive bead (2) (See Figure 2) 

. In this case, apply the rotor brake (braking position), move the blade, by hand, in the flapping and 

drag directions, in order to make sure that the bush (1) is correctly bonded. 

NOTE 1

Cracking is considered as a closed crack. It is distinguished by a single 

dimension (length). Cracking is the result of a minute displacement of bush 

(1) and is not necessarily combined with a bonding failure of the adhesive 

film between the bush and the arm end. 

CAUTION 

ANY MOVEMENT OF THE BUSH WHEN A LOAD IS APPLIED MUST BE 

CONSIDERED AS A REASON FOR REMOVAL. 

b) a gap (E1) between adhesive bead (2) and bush (1). (See Figure 3) 

NOTE 2

A gap (E1) is considered as an open crack. It is distinguished by two 

dimensions (length and width). This gap may be due to crack growth or 

bonding failure of bush (1) or distortion of the Starflex star arm end. 

CAUTION 

ANY GAP (E1) MUST BE CONSIDERED AS A REASON FOR REMOVAL 

EVEN IF THE BUSH DOES NOT MOVE WHEN A LOAD IS APPLIED AND 

EVEN IF THE GAP IS LOCATED ONLY ON PART OF THE 

CIRCUMFERENCE. 
 

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c) local loss of adhesive bead (2). (See Figure 5) 

CAUTION 

ON STARS PRE MOD 0762C18 (STARS NOT FITTED WITH 

SHOULDERED BUSHES ON THE STAR ARM END), ANY LOCAL LOSS 

OF ADHESIVE BEAD, WHATEVER ITS LOCATION, INDICATES THAT 

THE BUSH HAS MOVED, AND MUST ALSO BE CONSIDERED AS A 

REASON FOR REMOVAL. 

LOCAL LOSS OF ADHESIVE BEAD ON STARS POST MOD 0762C18

(STARS FITTED WITH SHOULDERED BUSHES ON THE STAR ARM 

END) IS PERMITTED ON THE CONDITION THAT PART OF THE 

ADHESIVE BEAD REMAINS ON THE LEADING EDGE THUS ENABLING 

TO CHECK THAT THERE IS NO GAP E1 (SEE FIGURES 1, 3 AND 5). 

2.B.2. Check for absence of delamination on the Starflex star arm ends 

As per Figure 4:

 On each Starflex star arm and on both sides (leading edge and trailing edge), make sure that there is no 

delamination in the composite material, in the area of the horizontal center plane, flush with the bush 

(zone A). If in doubt, carry out this check after having removed the paint coat by light cloth sanding. 

CAUTION 

ANY CRACK OR CRACKING IN THE AREA OF THE HORIZONTAL 

CENTER PLANE OF THE STAR ARM, FLUSH WITH BUSH (1), MUST BE 

CONSIDERED AS A REASON FOR REMOVAL OF THE STARFLEX 

STAR. 

2.B.3. Interpretation of the results 

a) If none of the removal criteria, specified in paragraphs 2.B.1. and 2.B.2. is reached: 

- Leave as is and resume flights. 

CAUTION 

CRACK-TYPE DETERIORATIONS, CRACKING AND LOSS OF 

ADHESIVE BEAD FROM THE INTERFACE BETWEEN THE BUSH AND 

THE STARFLEX STAR ARM END ARE REMOVAL CRITERIA AND MUST 

THEREFORE NOT BE FILLED OR SEALED. 

b) If one of the removal criteria, specified in paragraphs 2.B.1. and 2.B.2. is reached on one of the Starflex 

star arms: 

- Before resuming flights, remove and replace the Starflex star as per MET Work Card 62.20.00.401 

or 65.14.401. 

- Inform the EUROCOPTER Technical Support Department ESTVM by 

. Tel.: +33 (0)4.42.85.99.67 

. Fax: +33 (0)4.42.85.99.66 

. E-mail: DynComp.technical-support@eurocopter.com

- Return the Starflex star to EUROCOPTER Marignane for examination and repair where applicable. 
 

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2.C. IDENTIFICATION 

Record initial compliance with Revision 3 of this ALERT SERVICE BULLETIN in the aircraft documents. 

2.D. OPERATING AND MAINTENANCE INSTRUCTIONS 

Not applicable. 
 

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Figure 1 
 

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Figure 2 

Cracking 

Starflex star PRE MOD 0762C18

Starflex star POST MOD 0762C18
 

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Figure 3 

E1: Unacceptable
 

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Figure 4 

Delamination in 

Zone A: 

Unacceptable

Zone A
 

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Local loss of adhesive bead on stars post MOD 0762C18: Unacceptable in the leading edge (see 

CAUTION § 2.B.1.c) 

Figure 5 
 

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3. MATERIAL INFORMATION 

3.A. MATERIAL: COST - AVAILABILITY 

Not applicable. 

3.B. INFORMATION CONCERNING INDUSTRIAL SUPPORT 

Not applicable. 

3.C. MATERIAL REQUIRED FOR EACH AIRCRAFT, ENGINE/COMPONENTS 

Not applicable. 

3.D. PROCUREMENT CONDITIONS 

Order the required quantity (unless otherwise specified) 

from 

EUROCOPTER 

Etablissement de Marignane 

Direction Ventes et Relations Client 

ECR 

13725 MARIGNANE CEDEX 

FRANCE 

NOTE 1

On the purchase order, please specify the mode of 

transport, the destination and the serial numbers of the 

aircraft to be modified. 

NOTE 2

For ALERT SERVICE BULLETINS, order by: 

Telex: HELICOP 410 969F. 

4. APPENDIX 

Not applicable.